四川盆地碎屑岩领域有利天然气勘探方向浅析

四川盆地天然气主要分布于早期克拉通碳酸盐岩层系和晚期前陆层系碎屑岩领域中,由于碳酸盐岩层系中发育的气藏常常高含硫化氢,如罗家寨、渡口河等飞仙关组鲕滩气藏,储量动用难度大,因此,在四川盆地天然气勘探中,急需寻找低硫储量.前陆碎屑岩领域资源丰富,且低含硫,因此,该层系的有利勘探方向研究对指导盆地天然气勘探意义重大.通过四川盆地三大前陆盆地成藏研究,认为目前该层系首选勘探领域为龙门山前陆盆地,其次为米仓山和大巴山前陆盆地.有利勘探区带包括龙门山冲断带南段、梓潼凹陷、川中南部—蜀南构造带、龙门山冲断带北段、米仓山冲断带和大巴山冲断带.

Promising natural gas exploration belts in clastic rock formations, Sichuan Basin

The natural gas in Sichuan Basin mainly distributes in early cratonic carbonate rock strata series and late foreland clastic rock strata series.But the natural gas developed in the early cratonic carbonate rock strata series has high content of H_2S,which makes the development of it difficult.So it is urgent to find more natural gas with low content of H_2S.The rich natural gas resource exists in the late foreland clastic rock strata series,and the study of the favorable exploration strata series is of importance to the development of the natural gas in the basin.Through the study of three foreland basins in Sichuan Basin,it is held that the most favorable exploration target is Longmen Mountain foreland basin,and the secondary exploration targets are Micang Mountain and Daba Mountain foreland basins.The favorable exploration belts include the southern segment of Longmen Mountain thrust belt,Zitong Sag,structural belts in middle-southern—southern Sichuan Basin,the northern segment of Longmen Mountain thrust belt,Micang Mountain thrust and Daba Mountain thrust belt.